I asked my friend ChatGPT for a few HEXes to paint my snowman, by giving each model part by name. I was most surprised by the snow hex, as it gave me a "white" one, but with a very nice subtle hit of blue. Cute!
Just to expand on Martin's example. Hex colors are limited to 16.8(Rounded up) million colors also known as 24 bit color(32 bit if you count the alpha channel). Where HSV you have roughly around 32.6(Rounded up) million colors or 24/32bit Float HSV-1 standard. It may be more in blender since blender uses factor(0.000-1.000 with high precision) unlike Gimp which uses base values. I'm not sure if Blender uses HSV-1 or HSV-2 standard. HSV-2 is something like 4 billion colors with only a small fraction of those colors being visible thru sRGB monitor. That's probably more info than most people need or wanted, but just incase you where wondering why there can be so many variations of the same hex color in Blender.
Ooops! I didn't even think of color management effects on the end results. I'll have to add that to my studies. I normally don't touch color management except to change to false color for checking light clipping and standard for video editing. Otherwise I pretty much don't touch it.